Formation and alloying of elemental nanostructured β-W powders

N. C. Angastiniotis, B. H. Kear, L. E. McCandlish, K. V. Ramanujachary, M. Greenblatt

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


We have been investigating the reductive decomposition of spray dried ammonium metatungstate (AMT). Reduction of the pyrolysed powder in flowing hydrogen at T≥625°C creates a high surface area microcrystalline form of α-W, with bcc structure. Reduction at T≤575°C results in the formation of a high surface area nanocrystalline form of β-W, with A15 structure and chemical composition of W3O. The ideal A15 structure of W3O (isostructural with Nb3Sn) is a bcc lattice of oxygen atoms with tungsten atoms arranged in pairs on cube faces. In situ reduction experiments carried out in a controlled atmosphere, high temperature X-ray powder diffractometer have shown that W3O transforms to elemental β-W, in which all or nearly all of the oxygen atoms are absent. Various experiments confirming the existence of metastable elemental β-W are described. Initial experiments on its alloying behavior are also discussed.

Original languageAmerican English
Title of host publicationNovel Powder Processing
PublisherPubl by Metal Powder Industries Federation
Number of pages11
ISBN (Print)1878954261
StatePublished - 1992
EventProceedings of the 1992 Powder Metallurgy World Congress. Part 1 (of 9) - San Francisco, CA, USA
Duration: Jun 21 1992Jun 26 1992

Publication series

NameAdvances in Powder Metallurgy


OtherProceedings of the 1992 Powder Metallurgy World Congress. Part 1 (of 9)
CitySan Francisco, CA, USA

ASJC Scopus subject areas

  • Mechanical Engineering
  • Metals and Alloys

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